San Francisco is now part of a national study on the effectiveness of bike boxes.

Earlier this week, city transportation crews installed four green bike boxes on Market Street – two at the intersection of 9th Street and two at Van Ness Avenue.

Another is scheduled to be added at Market and Gough next week.

Similar boxes were placed in other neighborhoods several years ago, but these are the first to use a set of retro-reflective materials that shine at night.

The bike boxes are considered first of its kind in California, although similar programs are already underway in Portland and New York City.

San Francisco transportation officials said the goal is for motorists to be able to see bicyclists who are stopped in the boxes more easily.

The Municipal Transportation Agency said they plan to collect data on the effectiveness of the program and may expand it to other intersections.

Photo Credit: SF Streets Blog